Lever-type lathe chuck with replaceable jaw inserts

Abstract

A chuck has a chuck body adapted to be rotated about a chuck axis and a plurality of elongated jaw arms angularly spaced about the axis, pivotal in the chuck body about respective guide axes extending secantally of the chuck axis, and axially slidable in the body. Each jaw arm has a front outer end formed with a generally axially extending and radially inwardly directed outer face and an axially outwardly and forwardly directed inner face extending radially inward from an axially inner end of the outer face. Each outer face converges axially outward with the chuck axis and forms a small acute angle with the chuck axis. Respective jaw inserts each have a pair of faces complementary to and flatly engaging the respective jaw faces. These inserts are releasably secured to the jaw outer ends with the insert faces bearing on the jaw faces. The faces are planar. In addition each insert is formed with at least one throughgoing hole extending substantially parallel to the outer insert face. A screw fastener in the hole has a head bearing on the insert and a shank threaded into the outer end of the respective jaw arm.

I claim:  
     
       1. A chuck comprising: 
       a chuck body adapted to be rotated about a chuck axis;  
       a plurality of elongated jaw arms angularly spaced about the axis, pivotal in the chuck body about respective guide axes extending secantally of the chuck axis, and axially slidable in the body, each jaw arm having a front outer end formed with a generally axially extending and radially inwardly directed outer face and an axially outwardly and forwardly directed inner face extending radially inward from an axially inner end of the outer face, the outer faces each converging axially outward with the chuck axis and forming a small acute angle with the chuck axis;  
       respective jaw inserts each having a pair of faces complementary to and flatly engaging the respective jaw faces; and  
       means for releasably securing the inserts to the jaw outer ends with the insert faces bearing on the jaw faces.  
     
     
       2. The chuck defined in  claim 1  wherein the faces are planar. 
     
     
       3. The chuck defined in  claim 1  wherein each insert is formed with at least one throughgoing hole extending substantially parallel to the insert face, the means being a screw fastener in the hole and having a head bearing on the insert and a shank threaded into the outer end of the respective jaw arm. 
     
     
       4. The chuck defined in  claim 1  wherein each jaw has an inner gripping face extending generally parallel to the chuck axis. 
     
     
       5. The chuck defined in  claim 1  wherein each inner face extends at substantially 90° to the respective outer face. 
     
     
       6. The chuck defined in  claim 1  wherein each jaw has a flat front face diverging radially inward away from the respective inner face.